Traditionally, electronic percussion instruments (e.g., electronic drums) comprise a head (e.g., playing surface), composed of mesh, Mylar, or rubber material, attached to a housing (i.e., shell or cavity) and one or more sensors. The playing surface is usually made of a thin mesh (woven material), Mylar, or rubber material, and has an inferior end (i.e., bottom side) and a superior end (i.e., top side). The sensor typically comprises a flexible cushion material that is in contact with the inferior end of the playing surface mounted in the center of the drum, and an electromechanical transducer (piezoelectric transducer) positioned between the flexible cushion material and a supporting structure that is attached to the inner shell of the electronic percussion instrument. The supporting structure is generally a thin rigid material that is used to support the sensor.
Electronic percussion instruments are designed to transfer vibrations, induced by a user striking the superior end of a playing surface, to a flexible cushion material that is coupled to an electromechanical transducer that generates electrical signals in response to vibrations. These solutions are designed to give a varying electrical signal that can be interpreted by a drum module to determine how hard the surface was struck (i.e., magnitude). In some embodiments, a drum module can determine the magnitude and/or the location of the strike. The magnitude of the electrical signal (i.e., the amplitude of the velocity and/or force of the electrical signal) is determined by the shape, size, and location of the flexible cushion material, the sensor, and components (e.g., sensor plate) within the sensor. It is also determined by the location of the superior end of the playing surface that has been struck. Some modules may use the location and magnitude information to play different sounds or alterations to the current sound.
In many electronic percussion instruments, the flexible cushion material has a frustoconical shape, and the area of the flexible cushion material is considerably smaller than the entire area of the playing surface. The flexible cushion material is usually located in the center of the shell, and the superior end of the flexible cushion material is in contact with the inferior end of the playing surface. In such an orientation, a strike to the center of the superior end of the playing surface just above the flexible cushion material will cause the electromechanical transducer to generate an electrical signal with a magnitude that is greater than the magnitude of a signal corresponding to a strike further away from the center of the playing surface. Therefore, the sensitivity (i.e., magnitude of an electrical signal generated by an electromechanical transducer in response to a strike to a playing surface) is greater in the middle of the playing surface, as opposed to an area between the center and the perimeter of the playing surface. Thus, the area of the playing surface with the greatest sensitivity (i.e., sweet spot) is the area directly above the flexible cushion material. In most modern electronic percussion instruments, the area of the flexible cushion material is very small, thereby requiring a user to strike the superior end of the playing surface directly above the cushion material in order to generate a certain consistent sound. This design is appropriate for advanced users who are familiar with the sensitivity of a playing surface. However, novice and/or beginning users who are unfamiliar with the different areas of the playing surface, or have a lower degree of control or playing technique, have a harder time locating the sweet spot consistently. Existing designs make it difficult for novices and beginners to determine which area(s) of the playing surface should be struck in order to produce different sounds consistently.
An alternative design may enable a user to adjust the area of the sweet spot, thus enabling an electronic percussion instrument to reproduce a similar sound across a larger area of the playing surface. Multiple flexible cushion materials and electromechanical transducers of varying shapes and sizes can be used to adjust (i.e., increase or decrease) the area of sensitivity, thereby enabling an electronic percussion instrument to generate the same sound when a user strikes a portion of a playing surface corresponding to the adjusted area of sensitivity. By increasing the sweet spot, a user can strike the playing surface in a location that is not exactly at the center of the playing surface, and the electronic percussion instrument will produce the same sound that would be produced if the user struck the center of the playing surface. Conversely, as a user becomes more proficient at striking the playing surface in a sweet spot of a larger area, the user can reduce the area of the sweet spot thereby enabling a user to focus on striking different areas of a playing surface that correspond to an electronic percussion instrument producing different sounds.
Existing electronic percussion instruments are designed to generate differences in sensitivity levels across a playing surface due to the central location of a single flexible cushioning material. The present disclosure describes an electronic percussion instrument that can enable a user to adjust the differences in sensitivity levels across a playing surface, as well as maintain a constant sensitivity level across the entire playing surface.